Efficient centrifugal impact crusher with dust removal capability

Abstract

A centrifugal impact crusher has an enclosed table (22) to ensure that substantially all the material deposited on the table is impacted against the anvils (50) that surround the table. The table includes spaced-apart upper and lower plates (34, 28) that have radially oriented impellers (36) sandwiched between them to direct material being thrown off of the table by centrifugal force to exit the table at the proper angle to achieve maximum fracture upon striking the anvils (50). The impellers (36) have projecting tabs (38) which fit into receptacles (40) in the upper and lower plates (34, 28) and the plates are squeezed together to hold tabs (38) in the receptacles (40) and lock the plates and impellers together in a rigid table assembly (22). The upper plate (34) has a central opening (49) through which material is deposited onto the table. A funnel (60) directs material fed into the crusher through an infeed plenum (59) and into the central opening (49) in the upper plate (34) to ensure that all of the material reaches the table. Recirculation plenums (68) extend from an outlet plenum (51) located below the table up to the infeed plenum (59). The rotating table (22) acts as a fan which draws air into the infeed tube (58) along with the material, and this airflow creates a pressure differential across the table that causes air to flow through the recirculation plenum (68). The recirculation air includes dust and particulate matter which is either sent back through the crusher to be more finely crushed or is removed by filters. <IMAGE>

What is claimed is: 
     
       1. A centrifugal impact rock crusher of the type having an enclosed chamber, an infeed plenum that opens into the chamber, a rotating table having a series of radially arrayed impeller blades on its upper surface located in the chamber below said infeed plenum, a plurality of anvils located in the chamber around the periphery of the table substantially coplanar with the upper surface thereof, and an outlet plenum defined in the chamber below the table, said crusher comprising: (a) air removal means for removing air and airborne particles from the outlet plenum;   (b) means for recycling air and particles removed by said air removal means back into the infeed plenum; and   (c) filter means for receiving at least a portion of the air and particles removed by said air removal means and removing particles therefrom.   
     
     
       2. A centrifugal impact rock crusher of the type having an enclosed chamber, an infeed plenum that opens into the chamber, a rotating table having a series of radially arrayed impeller blades on its upper surface located in the chamber below said infeed plenum, a plurality of anvils located in the chamber around the periphery of the table substantially coplanar with the upper surface thereof, and an outlet plenum defined in the chamber below the table, said crusher comprising: (a) air removal means for removing air and airborne particles from the outlet plenum, said air removal means comprising one or more recirculation plenums that extend between the outlet plenum and the infeed plenum;   (b) a flow restrictor located in the infeed plenum upstream of said recirculation plenums.   
     
     
       3. A centrifugal impact rock crusher of the type having an enclosed chamber, an infeed plenum that opens into the chamber, a rotating table having a series of radially arrayed impeller blades on its upper surface located in the chamber below said infeed plenum, a plurality of anvils located in the chamber around the periphery of the table substantially coplanar with the upper surface thereof, and an outlet plenum defined in the chamber below the table, said crusher comprising: (a) air removal means for removing air and airborne particles from the outlet plenum, said air removal means including one or more recirculation plenums that extend between the outlet plenum and the infeed plenum;   (b) a flow restrictor located in the infeed plenum upstream of said recirculation plenums; wherein   (c) said recirculation plenums include outlets for connecting filters thereto.   
     
     
       4. A centrifugal impact rock crusher of the type having an enclosed chamber, an infeed plenum that opens into the chamber, a rotating table having a series of radially arrayed impeller blades on its upper surface located in the chamber below said infeed plenum, a plurality of anvils located in the chamber around the periphery of the table substantially coplanar with the upper surface thereof, and an outlet plenum defined in the chamber below the table, said crusher comprising: (a) air removal means for removing air and airborne particles from the outlet plenum; wherein   (b) the table includes: (i) a lower plate;   (ii) an upper plate that overlies said lower plate and defines a central opening that communicates with the infeed plenum;   (iii) upwardly and downwardly projecting tabs on said impellers, said upper and lower plates defining receptacles for receiving said tabs; and     (iv) clamp means for urging said upper and lower plates toward one another with said impellers located therebetween and said tabs received in said receptacles to create an integral enclosed table assembly.   
     
     
       5. A centrifugal impact rock crusher of the type having an enclosed chamber, an infeed plenum that opens into the chamber, a rotating table having a series of radially arrayed impeller blades on its upper surface located in the chamber below said infeed plenum, a plurality of anvils located in the chamber around the periphery of the table substantially coplanar with the upper surface thereof, and an outlet plenum defined in the chamber below the table, said crusher comprising: (a) air removal means for removing air and airborne particles from the outlet plenum; wherein   (b) the table includes (i) a lower plate;   (ii) an upper plate that overlies said lower plate and defines a central openings that communicates with the infeed plenum;   (iii) means for sandwiching the impellers between said upper and lower plates and creating an integral enclosed table assembly; (iv) an annular retainer plate that extends between an outer periphery of said upper plate and the anvils.     
     
     
       6. An table assembly for a centrifugal impact crusher of the type having an infeed tube, a rotating table located centrally below the infeed tube and having a series of radially arrayed impeller blades located on the upper surface thereof, and a plurality of anvils located around the periphery of the table substantially coplanar with the upper surface thereof, said table assembly comprising: (a) a lower plate;   (b) an upper plate that overlies said lower plate and defines a central opening the receives the infeed tube;   (c) mans for sandwiching the impellers between said upper and lower plates and creating an integral enclosed table assembly, said sandwiching means including: (i) upwardly and downwardly projecting tabs on said impellers;   (ii) said upper and lower plates defining receptacles for receiving said tabs;   (iii) said upper plate having a plurality of openings defined therein;   (iv) said lower plate having a plurality of pins extending upwardly therefrom, one of said pins extending through each of said openings;   (v) each of said pins having a slot defined therein proximate its upper extremity; and   (vi) wedges which pass through said slots.     
     
     
       7. The crusher of claim 3 wherein said recirculation plenums include adjustable flow control dampers downstream of said outlets. 
     
     
       8. The crusher of claim 4 wherein said clamp means comprises: (a) said lower plate having a plurality of threaded holes defined therein;   (b) said upper plate having a plurality of openings defined therein with one of said openings being aligned with each of said holes; and   (c) threaded fasteners that extend through said openings and into threaded engagement with said holes.   
     
     
       9. The crusher of claim 8, including wear-resistant shields that surround any portion of said fasteners that are exposed between said upper and lower plates. 
     
     
       10. The crusher of claim 4 wherein said clamp means comprises: (a) said upper plate having a plurality of openings defined therein;   (b) said lower plate having a plurality of pins extending upwardly therefrom, one of said pins extending through each of said openings;   (c) each of said pins having a slot defined therein proximate its upper extremity; and   (d) wedges which pass through said slots.   
     
     
       11. The crusher of claim 10, including wear resistant shields that surround any portion of said pins that are exposed between said upper and lower plates. 
     
     
       12. The table assembly of claim 6, including wear resistant shields that surround any portion of said pins that are exposed between said upper and lower plates.